Searching for a new job is a stressful and time-consuming task. When I moved to London a couple of months ago I had this experience once again and I was overwhelmed by the amount of online resources to "help" candidates find a perfect job. I was lucky enough to find an awesome place to work and during the process I learn a few tricks that can make this task easier.
Set up a search on Twitter and keep yourself updated
I use Tweetdeck but I reckon any Twitter client should do. Make a search using keywords like "front-end dev job", "web design position", etc. and set it up as a column. This is very helpful as it allows you to measure the market plus you'll be able to see the job offers as they are published. If you have a city in mind, it's a good idea to use it as a keyword as well to filter your search. I used "front-end jobs london" for a while and had good results. The bad side of Twitter is that there is a lot of retweeting among job agencies so you might get a busy timeline.
Create accounts in job boards sites... but not too many!
This is probably the main source of job offers you'll find online but is also the most boring one. You'll have to fill huge forms, answer a million questions and upload your CV in a file format specific for each site. I recommend to pic one or two that you find are more relevant for your position and stick to them. Most agencies will republish offers in different sites anyway so save your time and patience.
HR Agencies
You can skip the searching and let someone else do it for you. The web market is very good these days so you'll have offers in no time. However, bear in mind that their job is to people so they will phone you daily pushing "amazing" positions that barely fit your profile.
Job boards and independent sites
There is loads of job boards online that let you contact the company directly. This is usually what startups or small companies prefer to use since they don't have the budget to hire HR agencies and prefer to do the hiring by themselves. The problem with this approach is that you will see a lot of ads offers of jobs that are either expired or were already taken. If you use these sites, keep your search to the most recent ones. Offers dated over a month are probably taken.
RSS, anyone?
Another option is to subscribe to a few job sites that serve RSS feeds and organize them in aggregators like Google Reader.
So you got a job...
After your search is done and you landed a job I strongly recommend you to delete your account or update your details stating you are no longer in need of a new position... because you will get tons of e-mails and you will get annoying calls. So spend a couple of minutes and free yourself of this. Seriously.